using InnovEnergy.Lib.Protocols.Modbus.Protocol.Frames.Accessors;
using static InnovEnergy.Lib.Protocols.Modbus.Protocol.FunctionCode;

namespace InnovEnergy.Lib.Protocols.Modbus.Protocol.Frames.Replies;

using UInt16s = IReadOnlyList<UInt16>;

internal class ReadHoldingRegistersResponseFrame : ModbusFrame
{

    internal new const Int32 MinSize = 3;

    public MbByte  ByteCount     => Data.ByteAt(2);
    public MbRegisters RegistersRead => Data.RegistersAt(3);


    public ReadHoldingRegistersResponseFrame(Byte slave, UInt16s registersRead) : base(ExpectedSize(registersRead.Count))
    {
        SlaveAddress .Set(slave);
        FunctionCode .Set(ReadHoldingRegisters);
        ByteCount    .Set(registersRead.Count * 2);
        RegistersRead.Set(registersRead);
    }

    internal static Int32 ExpectedSize(Int32 nRegisters) => MinSize + nRegisters * 2;

    private ReadHoldingRegistersResponseFrame(Byte[] data) : this(new ArraySegment<Byte>(data))
    { }


    private ReadHoldingRegistersResponseFrame(ArraySegment<Byte> data) : base(data)
    {
        if (data.Count < MinSize)
            throw new ArgumentOutOfRangeException($"Expecting an array of size {MinSize} or more", nameof(data));

        AssertFunctionCode(ReadHoldingRegisters);

        var expectedSize = ByteCount + MinSize;
        if (data.Count != expectedSize)
            throw new ArgumentOutOfRangeException($"Expecting an array of size {expectedSize}", nameof(data));

        if (ByteCount != RegistersRead.Count * 2)
            throw new ArgumentException(nameof(RegistersRead));
    }


    public static ReadHoldingRegistersResponseFrame Parse(ModbusFrame frame)       => new ReadHoldingRegistersResponseFrame(frame.Data);
    public static ReadHoldingRegistersResponseFrame Parse(Byte[] data)             => new ReadHoldingRegistersResponseFrame(data);
    public static ReadHoldingRegistersResponseFrame Parse(ArraySegment<Byte> data) => new ReadHoldingRegistersResponseFrame(data);
}